Police recovered a bag containing a sawed-off rifle believed to have been used in the killings. They say the balding Perrone appeared on surveillance footage carrying the bag moments after the most recent shooting, last Friday.

The other killings happened in July and August. All three shopkeepers were men alone in stores that had no video cameras.

Perrone is in custody and can't be reached for comment. It's unclear if he has a lawyer. A message left on his cellphone hasn't been returned.